WASHINGTON — Senate Republican leaders on Wednesday demonstrated the fissures that continue to linger over proposals to overhaul the nation’s immigration laws.

The Senate is largely seen as the chamber that will have to lead efforts to pass any form of legislative change. But the upper chamber’s first hearing on comprehensive immigration reform revealed some Republicans’ strong fears that border security will be left by the wayside in any agreement.

“This is like deja vu for a lot of us,” Senate Minority Whip John Cornyn, R-Texas, said at the hearing of the Senate Judiciary Committee. “I believe that the reason immigration reform failed in 2007 is because the American people don’t actually believe that Congress intends to follow through on important measures like border security, worksite enforcement, visa overstays and the like.”

Homeland Security Secretary Janet Napolitano testified on behalf of a comprehensive package. She called the “‘border security first’ refrain” an excuse that ignored progress on the border. She then shared a list of numbers that showed the U.S. Border Patrol has doubled from 10,000 agents in 2004 to more than 21,000 today, and that apprehensions have been cut by 49 percent in the past four years.

“Our borders in fact have never been stronger,” she said.

The immigration debate was thrust back into the national spotlight after Latinos demonstrated their political prowess in the November election.

President Barack Obama, who won re-election with 71 percent of the Latino vote, as well as a bipartisan group of senators, have since introduced proposals that call for a path to citizenship for the nation’s estimated 11 million illegal immigrants. A bipartisan group of members of the House of Representatives also is working on proposals.

In his State of the Union address Tuesday night, Obama emphasized the economic benefits of overhauling the country’s immigration laws.

He was expected to meet Wednesday with the four Democrats in the Senate bipartisan effort: Sens. Chuck Schumer of New York, Richard Durbin of Illinois, Michael Bennet of Colorado and Robert Menendez of New Jersey. The Republicans in the group — who aren’t part of the White House meeting — include Sens. Marco Rubio of Florida, John McCain of Arizona, Lindsey Graham of South Carolina and Jeff Flake of Arizona.

“I think the country is tired of talking about it. I think it’s time to fix it,” said Graham, who is a member of the Judiciary Committee.

Also testifying at the hearing were journalist-turned-activist Jose Antonio Vargas, AOL co-founder Steve Case and Janet Murguia, president of the National Council of La Raza, an advocacy organization.

Senators also called on Jessica Vaughan, director of policy studies at the Center for Immigration Studies, a research organization that supports tougher enforcement measures, and Chris Crane, president of the union for U.S. Immigration and Customs Enforcement, who criticized the lack of enforcement and questioned the authenticity of promises that greater enforcement would be part of a comprehensive package.

“I think most Americans assume that ICE agents and officers are empowered by our government to enforce the law,” Crane said. “Nothing can be further from the truth. With 11 million illegal aliens in the U.S., ICE agents are now prohibited from arresting illegal aliens solely on charges of illegal entry or visa overstay, the two most frequently violated sections of U.S. immigration law.”

The Obama administration announced in December that illegal immigrants who are arrested in minor crimes no longer will be targeted for deportation.